Motor and control unit thereof

Abstract

A motor and a control unit therefor comprise: salient rotor poles and salient stator poles, which are arranged along circumferences of phases A, B and C with an even interval therebetween; magnetic paths for passing magnetic fluxes, the paths permitting the magnetic fluxes passing through the salient rotor and stator poles of each phase to return to the rotor side; and substantially looped windings arranged between the salient stator poles of individual phases and the magnetic paths for passing magnetic fluxes, wherein currents are supplied to the windings in synchronization with the rotational position of the rotor to thereby output torque. Since the structures of the stator, the rotor and the windings are simple, productivity is enhanced, whereby high quality, small size and low cost can be realized.

The invention claimed is: 
     
       1. An N-phased (N is an integer of four or more) AC electric motor comprising:
 a stator; 
 a rotor arranged opposed to the stator, the rotor having a shaft disposed in an axial direction of the motor about which the rotor rotates; 
 a plurality of stator salient poles and a plurality of rotor salient poles, which are respectively provided as N sets for an N number of phases, the plurality of stator salient poles for each phase being arranged along a circumference of the stator at a corresponding N position in the axial direction of the motor and the plurality of rotor salient poles for each phase being arranged along a circumference of the rotor at the corresponding N position in the axial direction of the motor so as to be opposed to the stator salient poles for each phase, 
 a stator-flux-passing magnetic path arranged along the circumference of the stator at a different position in the axial direction of the motor and formed to allow magnetic fluxes to pass through the stator; 
 a rotor-flux-passing magnetic path arranged along the circumference of the rotor at the different position in the axial direction of the motor so as to be opposed to the stator-flux-passing magnetic path and formed to allow the magnetic fluxes to pass through the rotor; 
 a stator back yoke magnetic path magnetically shared between the stator salient poles for the N number of phases and the stator-flux-passing magnetic path; 
 a rotor back yoke magnetic path magnetically shared between the rotor salient poles for the N number of phases and the rotor-flux-passing magnetic path; and 
 an (N−1) number of substantially looped windings arranged between the stator salient poles for the N number of phases and the stator-flux-passing magnetic path. 
 
     
     
       2. An N-phased (N is an integer of four or more) AC electric motor comprising:
 a stator; 
 a rotor arranged opposed to the stator, the rotor having a shaft disposed in an axial direction of the motor about which the rotor rotates; 
 a plurality of stator salient poles and a plurality of rotor salient poles, which are respectively provided as N sets for an N number of phases, the plurality of stator salient poles for each phase being arranged along a circumference of the stator at a corresponding N position in the axial direction of the motor and the plurality of rotor salient poles for each phase arranged along a circumference of the rotor at the corresponding N position in the axial direction of the motor so as to be opposed to the stator salient poles for each phase, 
 a stator back yoke magnetic path magnetically shared among the stator salient poles for the N number of phases; 
 a rotor back yoke magnetic path magnetically shared among the rotor salient poles for the N number of phases; and 
 an (N−1) number of substantially looped windings arranged between the stator salient poles for the N number of phases. 
 
     
     
       3. An AC electric motor comprising:
 a stator; 
 a rotor arranged to be opposed to the stator, the rotor having a shaft disposed in an axial direction of the motor about which the rotor rotates; 
 a plurality of first stator salient poles arranged along a circumference of the stator at a first position in the axial direction of the motor; 
 a plurality of first rotor salient poles arranged along a circumference of the rotor at the first position in the axial direction of the motor so as to be opposed to the first stator salient poles; 
 a plurality of second stator salient poles arranged along the circumference of the stator at a second position in the axial direction of the motor; 
 a plurality of second rotor salient poles arranged along the circumference of the rotor at the second position in the axial direction of the motor so as to be opposed to the second stator salient poles; 
 a stator-flux-passing magnetic path arranged along the circumference of the stator at a third position in the axial direction of the motor and formed to allow magnetic fluxes to pass through the stator; 
 a rotor-flux-passing magnetic path arranged along the circumference of the rotor at the third position in the axial direction of the motor and formed to allow the magnetic fluxes to pass through the rotor; 
 a stator back yoke magnetic path magnetically shared among the first stator salient poles, the second stator salient poles and the stator-flux-passing magnetic path; 
 a rotor back yoke magnetic path magnetically shared among the first rotor salient poles, the second rotor salient poles and the rotor-flux-passing magnetic path; and 
 a plurality of substantially looped windings, one of the plurality of substantially looped windings being arranged between the first stator salient soles and the stator-flux-passing magnetic path, and an other of the plurality of substantially looped windings being arranged between the second stator salient poles and the stator-flux-passing magnetic path, wherein 
 the first and second stator salient poles and the first and second rotor salient poles are formed such that first and second the stator salient poles have faces each having a stator's opposing shape opposed to the rotor, and the first and second rotor salient poles having faces each having a rotor's opposing shape opposed to the stator, the stator's opposing shape and the rotor's opposing shape being opposed to each other to provide a mutually opposed shape which changes with a rotational angle of the rotor; 
 the mutually opposed shape has an area of which rotation rate changes with the rotational angle of the rotor in a rotational range of the rotor, from a rotational angle at which the mutually opposed shape is initiated with the encountering of stator and rotor salient poles with each other, to a rotational angle at which the mutually opposed shape is eliminated with the parting of the stator and rotor salient poles from each other, and 
 rotation of the rotor in one direction generates more serial rotating torque than rotation of the rotor in the other direction. 
 
     
     
       4. An AC electric motor comprising:
 a stator; 
 a rotor arranged to be opposed to the stator, the rotor having a shaft disposed in an axial direction of the motor about which the rotor rotates; 
 a plurality of first stator salient poles arranged along a circumference of the stator at a first position in the axial direction of the motor; 
 a plurality of first rotor salient poles arranged along a circumference of the rotor at the first position in the axial direction of the motor so as to be opposed to the first stator salient poles; 
 a plurality of second stator salient poles arranged along the circumference of the stator at a second position in the axial direction of the motor; 
 a plurality of second rotor salient poles arranged along the circumference of the rotor at the second position in the axial direction of the motor so as to be opposed to the second stator salient poles; 
 a stator-flux-passing magnetic path arranged along the circumference of the stator at a third position in the axial direction of the motor and formed to allow magnetic fluxes to pass through the stator; 
 a rotor-flux-passing magnetic path arranged along the circumference of the rotor at the third position in the axial direction of the motor and formed to allow the magnetic fluxes to pass through the rotor; 
 a stator back yoke magnetic path magnetically shared among the first stator salient poles, the second stator salient poles and the stator-flux-passing magnetic path; 
 a rotor back yoke magnetic path magnetically shared among the first rotor salient poles, the second rotor salient poles and the rotor-flux-passing magnetic path; and 
 a plurality of substantially looped windings, one of the plurality of substantially looped windings being arranged between the first stator salient poles and the stator-flux-passing magnetic path, and an other of the plurality of substantially looped windings being arranged between the second stator salient poles and the stator-flux-passing magnetic path, wherein 
 at least one of the stator salient poles and the rotor salient poles have base portions each united with a center portion of each salient pole and in a direction radial to the rotor shaft, and 
 the base portion has a shape bulged in a circumferential direction of the rotor. 
 
     
     
       5. An AC electric motor comprising:
 a stator; 
 a rotor arranged to be opposed to the stator, the rotor having a shaft disposed in an axial direction of the motor about which the rotor rotates; 
 a plurality of first stator salient poles arranged along a circumference of the stator at a first position in the axial direction of the motor; 
 a plurality of first rotor salient poles arranged along a circumference of the rotor at the first position in the axial direction of the motor so as to be opposed to the first stator salient poles; 
 a plurality of second stator salient poles arranged along the circumference of the stator at a second position in the axial direction of the motor; 
 a plurality of second rotor salient poles arranged along the circumference of the rotor at the second position in the axial direction of the motor so as to be opposed to the second stator salient poles; 
 a stator-flux-passing magnetic path arranged along the circumference of the stator at a third position in the axial direction of the motor and formed to allow magnetic fluxes to pass through the stator; 
 a rotor-flux-passing magnetic Bath arranged along the circumference of the rotor at the third position in the axial direction of the motor and formed to allow the magnetic fluxes to pass through the rotor; 
 a stator back yoke magnetic path magnetically shared among the first stator salient poles, the second stator salient poles and the stator-flux-passing magnetic path; 
 a rotor back yoke magnetic path magnetically shared among the first rotor salient poles, the second rotor salient poles and the rotor-flux-passing magnetic path; 
 a plurality of substantially looped windings, one of the plurality of substantially looped windings being arranged between the first stator salient poles and the stator-flux-passing magnetic path, and an other of the plurality of substantially looped windings being arranged between the second stator salient poles and the stator-flux-passing magnetic path; 
 a cooling mechanism having a structure of passing liquid or gas therethrough; and 
 the cooling mechanism being located one of inside of a soft magnetic material of a stator, or between the soft magnetic material of the stator and windings of the motor. 
 
     
     
       6. An AC electric motor comprising:
 a stator; 
 a rotor arranged to be opposed to the stator, the rotor having a shaft disposed in an axial direction of the motor about which the rotor rotates; 
 a plurality of first stator salient poles arranged along a circumference of the stator at a first position in the axial direction of the motor; 
 a plurality of first rotor salient poles arranged along a circumference of the rotor at the first position in the axial direction of the motor so as to be opposed to the first stator salient poles; 
 a plurality of second stator salient poles arranged along the circumference of the stator at a second position in the axial direction of the motor; 
 a plurality of second rotor salient poles arranged along the circumference of the rotor at the second position in the axial direction of the motor so as to be opposed to the second stator salient poles; 
 a stator-flux-passing magnetic path arranged along the circumference of the stator at a third position in the axial direction of the motor and formed to allow magnetic fluxes to pass through the stator; 
 a rotor-flux-passing magnetic path arranged along the circumference of the rotor at the third position in the axial direction of the motor and formed to allow the magnetic fluxes to pass through the rotor; 
 a stator back yoke magnetic path magnetically shared among the first stator salient poles, the second stator salient poles and the stator-flux-passing magnetic path; 
 a rotor back yoke magnetic path magnetically shared among the first rotor salient poles, the second rotor salient poles and the rotor-flux-passing magnetic path; 
 a plurality of substantially looped windings, one of the plurality of substantially looped windings being arranged between the first stator salient poles and the stator-flux-passing magnetic path, and an other of the plurality of substantially looped windings being arranged between the second stator salient poles and the stator-flux-passing magnetic path; and 
 a cooling mechanism in which a portion or all of windings of the motor are made up of metal pipes serving as conductors, and liquid or gas is passed through the metal pipes. 
 
     
     
       7. An AC electric motor comprising:
 a stator; 
 a rotor arranged to be opposed to the stator, the rotor having a shaft disposed in an axial direction of the motor about which the rotor rotates; 
 a plurality of first stator salient poles arranged along a circumference of the stator at a first position in the axial direction of the motor; 
 a plurality of first rotor salient poles arranged along a circumference of the rotor at the first position in the axial direction of the motor so as to be opposed to the first stator salient poles; 
 a plurality of second stator salient poles arranged along the circumference of the stator at a second position in the axial direction of the motor; 
 a plurality of second rotor salient poles arranged along the circumference of the rotor at the second position in the axial direction of the motor so as to be opposed to the second stator salient poles; 
 a stator-flux-passing magnetic path arranged along the circumference of the stator at a third position in the axial direction of the motor and formed to allow magnetic fluxes to pass through the stator; 
 a rotor-flux-passing magnetic path arranged along the circumference of the rotor at the third position in the axial direction of the motor and formed to allow the magnetic fluxes to pass through the rotor; 
 a stator back yoke magnetic path magnetically shared among the first stator salient poles, the second stator salient poles and the stator-flux-passing magnetic path; 
 a rotor back yoke magnetic path magnetically shared among the first rotor salient poles, the second rotor salient poles and the rotor-flux-passing magnetic path; and 
 a plurality of substantially looped windings, one of the plurality of substantially looped windings being arranged between the first stator salient Doles and the stator-flux-passing magnetic path, and an other of the plurality of substantially looped windings being arranged between the second stator salient poles and the stator-flux-passing magnetic path, wherein 
 each of the windings has substantially a looped shape which is wavy in a direction radial to the rotor shaft in response to an arrangement of the first and second stator salient poles of each phase and indents of the first and second stator salient poles in the direction radial to the rotor shaft. 
 
     
     
       8. An AC electric motor comprising:
 a stator; 
 a rotor arranged to be opposed to the stator, the rotor having a shaft disposed in an axial direction of the motor about which the rotor rotates; 
 a plurality of first stator salient poles arranged along a circumference of the stator at a first position in the axial direction of the motor; 
 a plurality of first rotor salient poles arranged along a circumference of the rotor at the first position in the axial direction of the motor so as to be opposed to the first stator salient poles; 
 a plurality of second stator salient poles arranged along the circumference of the stator at a second position in the axial direction of the motor; 
 a plurality of second rotor salient poles arranged along the circumference of the rotor at the second position in the axial direction of the motor so as to be opposed to the second stator salient poles; 
 a stator-flux-passing magnetic path arranged along the circumference of the stator at a third position in the axial direction of the motor and fowled to allow magnetic fluxes to pass through the stator; 
 a rotor-flux-passing magnetic path arranged along the circumference of the rotor at the third position in the axial direction of the motor and formed to allow the magnetic fluxes to pass through the rotor; 
 a stator back yoke magnetic path magnetically shared among the first stator salient poles, the second stator salient poles and the stator-flux-passing magnetic path; 
 a rotor back yoke magnetic path magnetically shared among the first rotor salient poles, the second rotor salient poles and the rotor-flux-passing magnetic path; and 
 a plurality of substantially looped windings, one of the plurality of substantially looped windings being arranged between the first stator salient poles and the stator-flux-passing magnetic path, and an other of the plurality of substantially looped windings being arranged between the second stator salient poles and the stator-flux-passing magnetic path, wherein 
 the stator-flux-passing magnetic path and the rotor-flux-passing magnetic path each include a magnetic path arranged along the circumference of the stator and the rotor, respectively, and magnetically coupling the stator and the rotor; 
 each of the first and second stator salient poles include a first subset of stator salient poles arranged along the circumference of the stator so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated; 
 each of the first and second rotor salient poles include a first subset of rotor salient poles arranged along a circumference of the rotor so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated, the first subset of rotor salient poles being radially opposed to the first subset of stator salient poles; 
 the windings include a first winding arranged between the magnetic path arranged along the circumference of the stator and the rotor and the first subset of stator salient poles; 
 the first and second stator salient poles further include a second subset of stator salient poles arranged along the circumference of the stator so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated, the second subset of stator salient poles being adjacent to the stator-flux-passing magnetic path and the rotor-flux-passing magnetic path; 
 the first and second rotor salient poles further include a second subset of rotor salient poles arranged along the circumference of the rotor so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated, the second set of rotor salient poles being radially opposed to the second subset of stator poles; and 
 the windings further include a second winding arranged between the first subset of stator salient poles and the second subset of stator salient poles, and 
 the motor further comprises:
 a third winding; 
 first, second, third and fourth power elements capable of on/off control of currents passing through the power elements; and 
 drive means for driving the power elements, 
 
 wherein 
 one end of each of the first power element and the third power element is connected to a positive terminal of a DC power source; 
 one end of each of the second power element and the fourth power element is connected to a negative terminal of the DC power source; 
 any one of the first, second and third windings is connected between the first power element and the second power element; 
 any other one of the first, second and third windings is connected between the third power element and the fourth power element; 
 any other one of the windings is connected between the first power element and the fourth power element; and 
 the drive means drives the power elements such that, 
 when torque is to be generated between the first subset of stator salient poles and the first subset of rotor salient poles, the two power elements connected with the first winding are driven for current supply, and at the same time, the two power elements connected with the second winding are driven for current supply; and 
 when torque is to be generated between the second subset of stator salient poles and the second subset of rotor salient poles, the two power elements connected with the second winding are driven for current supply. 
 
     
     
       9. An AC electric motor comprising:
 a stator; 
 a rotor arranged to be opposed to the stator, the rotor having a shaft disposed in an axial direction of the motor about which the rotor rotates; 
 a plurality of first stator salient poles arranged along a circumference of the stator at a first position in the axial direction of the motor; 
 a plurality of first rotor salient poles arranged along a circumference of the rotor at the first position in the axial direction of the motor so as to be opposed to the first stator salient poles; 
 a plurality of second stator salient poles arranged along the circumference of the stator at a second position in the axial direction of the motor; 
 a plurality of second rotor salient poles arranged along the circumference of the rotor at the second position in the axial direction of the motor so as to be opposed to the second stator salient poles; 
 a stator-flux-passing magnetic path arranged along the circumference of the stator at a third position in the axial direction of the motor and formed to allow magnetic fluxes to pass through the stator; 
 a rotor-flux-passing magnetic path arranged along the circumference of the rotor at the third position in the axial direction of the motor and formed to allow the magnetic fluxes to pass through the rotor; 
 a stator back yoke magnetic path magnetically shared among the first stator salient poles, the second stator salient poles and the stator-flux-passing magnetic path; 
 a rotor back yoke magnetic path magnetically shared among the first rotor salient poles, the second rotor salient poles and the rotor-flux-passing magnetic path; and 
 a plurality of substantially looped windings, one of the plurality of substantially looped windings being arranged between the first stator salient poles and the stator-flux-passing magnetic path, and an other of the plurality of substantially looped windings being arranged between the second stator salient poles and the stator-flux-passing magnetic path, wherein 
 the stator-flux-passing magnetic path and the rotor-flux-passing magnetic path each include a magnetic path arranged along a circumference of the stator and the rotor, respectively, and magnetically coupling the stator and the rotor; 
 the first and second stator salient poles include a first subset of stator salient poles arranged along the circumference of the stator so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated; 
 the first and second rotor salient poles include a first subset of rotor salient poles arranged along a circumference of the rotor so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated, the first subset of rotor salient poles being radially opposed to the first subset of stator salient poles; 
 the windings include a first winding arranged between the magnetic path arranged along the circumference of the stator and the rotor and the first subset of stator salient poles; 
 the first and second stator salient poles further include a second subset of stator salient poles arranged along the circumference of the stator so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated, the second subset of stator salient poles being adjacent to the first subset of stator salient poles; 
 the first and second rotor salient poles further include a second subset of rotor salient poles arranged along the circumference of the rotor so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated, the second subset of rotor salient poles being radially opposed to the second subset of stator salient poles; and 
 the windings further include a second winding arranged between the first subset of stator salient poles and the second subset of stator salient poles, and 
 the motor further comprises:
 a third winding; 
 first, second, third and fourth power elements capable of on/off control of currents passing therethrough; and 
 drive means for driving the power elements; 
 
 wherein 
 one end of each of the first power element and the third power element is connected to a positive terminal of a DC power source; 
 one end of each of the second power element and the fourth power element is connected to a negative terminal of the DC power source; 
 the second winding is connected between the first power element and the second power element; 
 the third winding is connected between the third power element and the fourth power element; 
 the first winding is connected between the second power element and the fourth power element, or between the first power element and the third power element; 
 the drive means drives the power elements such that 
 when torque is to be generated between the second subset of stator salient poles and the second subset of rotor salient poles, the first and second power elements are driven for current supply to the second winding; and 
 when torque is to be generated between the first subset of stator salient poles and the first subset of rotor salient poles, the first and fourth power elements are driven for serial current supply to the first winding and the second winding. 
 
     
     
       10. An AC electric motor comprising:
 a stator; 
 a rotor arranged to be opposed to the stator, the rotor having a shaft disposed in an axial direction of the motor about which the rotor rotates; 
 a plurality of first stator salient poles arranged along a circumference of the stator at a first position in the axial direction of the motor; 
 a plurality of first rotor salient poles arranged along a circumference of the rotor at the first position in the axial direction of the motor so as to be opposed to the first stator salient poles; 
 a plurality of second stator salient poles arranged along the circumference of the stator at a second position in the axial direction of the motor; 
 a plurality of second rotor salient poles arranged along the circumference of the rotor at the second position in the axial direction of the motor so as to be opposed to the second stator salient poles; 
 a stator-flux-passing magnetic path arranged along the circumference of the stator at a third position in the axial direction of the motor and formed to allow magnetic fluxes to pass through the stator; 
 a rotor-flux-passing magnetic path arranged along the circumference of the rotor at the third position in the axial direction of the motor and formed to allow the magnetic fluxes to pass through the rotor; 
 a stator back yoke magnetic path magnetically shared among the first stator salient poles, the second stator salient poles and the stator-flux-passing magnetic path; 
 a rotor back yoke magnetic path magnetically shared among the first rotor salient poles, the second rotor salient poles and the rotor-flux-passing magnetic path; and 
 a plurality of substantially looped windings, one of the plurality of substantially looped windings being arranged between the first stator salient poles and the stator-flux-passing magnetic path, and an other of the plurality of substantially looped windings being arranged between the second stator salient poles and the stator-flux-passing magnetic path, wherein 
 the stator-flux-passing magnetic path and the rotor-flux-passing magnetic path each include a magnetic path arranged along a circumference of the stator and rotor and magnetically coupling the stator and the rotor; 
 each of the first and second stator salient poles include a first subset of stator salient poles arranged along the circumference of the stator so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated; 
 each of the first and second rotor salient poles include a first subset of rotor salient poles arranged along the circumference of the rotor so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated, the first subset of rotor salient poles being radially opposed to the first subset of stator salient poles; 
 the windings include a first winding arranged between the magnetic path and the first subset of stator salient poles; 
 the first and second stator salient poles further include a second subset of stator salient poles arranged along the circumference so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated, the second subset of stator salient poles being adjacent to the first subset of stator salient poles; 
 the first and second rotor salient poles further include a second subset of rotor salient poles arranged along the circumference so that portions having large magnetic resistance and portions having small magnetic resistance are substantially alternated, the second subset of rotor salient poles being radially opposed to the second subset of stator salient poles; and 
 the windings further include a second winding arranged between the first subset of stator salient poles and the second subset of stator salient poles, and 
 the motor further comprises:
 a third winding; 
 first, second, third and fourth power elements capable of on/off control of currents passing therethrough; and 
 drive means for driving the power elements, 
 
 wherein 
 one end of each of the first power element and the third power element is connected to a positive terminal of a DC power source; 
 one end of each of the second power element and the fourth power element is connected to a negative terminal of the DC power source; 
 the second winding is connected between the first power element and the second power element; 
 the third winding is connected between the third power element and the second power element; 
 the first winding is connected between the second power element and the fourth power element; and 
 the drive means drives the power elements such that 
 when torque is to be generated between the second subset of stator salient poles and the second subset of rotor salient poles, the first and second power elements are driven for current supply to the second winding; and 
 when torque is to be generated between the first subset of stator salient poles and the first subset of rotor salient poles, the first and fourth power elements are driven for serial current supply to the first winding and the second winding.